Anachronisms: In one scene, Beethoven refers to his "Moonlight Sonata" (Sonata 14, Opus 27, No. 2). However, the piece did not come to be known as "Moonlight" until 1832, several years after Beethoven's death, when it was given the nickname by poet Ludwig Rellstab. The true title of the piece, as Beethoven wrote it, is "Quasi una Fantasia".
Factual errors: The movie is set in 1824 during the composition of Beethoven's 9th Symphony. Throughout the movie Beethoven is shown to be hard of hearing but quite capable of understanding people who speak loudly. In reality, Beethoven had totally lost his hearing seven years earlier (1817). The 9th Symphony was composed while he was completely deaf.
Continuity: After Anna Holtz catches Karl van Beethoven stealing and Karl runs out the door, Anna quickly runs to her desk takes off her jacket. In the next shot it is back on and she takes it off again.
Factual errors: The film depicts Beethoven conducting the premier of his Ninth Symphony with Anna's help and at the end her turning him around at the podium to see the thunderous applause. In reality, Michael Umlauf conducted and although Beethoven was on stage keeping tempo, the orchestra had been told to ignore him. At the end of the performance it was one of the soloists, Caroline Unger, who turned him around to see the enthusiastic applause of the audience.
Anachronisms: During the performance of the 9th, the trumpet player is shown playing a European style rotary valve trumpet with clock-spring valves (Riedl?) that were first developed in 1835. The design of the trumpet is also of later vintage, as most trumpets of this era lacked valves, the keyed bugle, Haydn's keyed trumpet and instruments with Stolzel valves being the new technology. Finally, the mouthpiece has a very modern profile, perhaps of the 20th Century.
Incorrectly regarded as goofs: When Beethoven is berating Schlemmer, he yells, "B-flat! B-flat! B-flat!" and hits a chord 3 times. The chord he hits on the piano sounds like a modern A-flat major chord, even though Beethoven is clearly hitting a chord with a top note of F. The reason for the discrepancy is probably because the pitch for tuning instruments has changed over time, and a frequency that would today be called an "A-flat" would have in Beethoven's time been something between an A and B-flat.
Factual errors: Early on, in her scene with Schlemmer, Anna informs us that the premier will be on Sunday. May 7, 1824, was in fact a Friday.